1 // SPDX-License-Identifier: GPL-2.0+
3 * Core registration and callback routines for MTD
6 * Copyright © 1999-2010 David Woodhouse <dwmw2@infradead.org>
7 * Copyright © 2006 Red Hat UK Limited
12 #include <dm/devres.h>
13 #include <linux/module.h>
14 #include <linux/kernel.h>
15 #include <linux/ptrace.h>
16 #include <linux/seq_file.h>
17 #include <linux/string.h>
18 #include <linux/timer.h>
19 #include <linux/major.h>
21 #include <linux/err.h>
22 #include <linux/ioctl.h>
23 #include <linux/init.h>
24 #include <linux/proc_fs.h>
25 #include <linux/idr.h>
26 #include <linux/backing-dev.h>
27 #include <linux/gfp.h>
28 #include <linux/slab.h>
30 #include <linux/err.h>
31 #include <ubi_uboot.h>
34 #include <linux/log2.h>
35 #include <linux/mtd/mtd.h>
36 #include <linux/mtd/partitions.h>
42 * backing device capabilities for non-mappable devices (such as NAND flash)
43 * - permits private mappings, copies are taken of the data
45 static struct backing_dev_info mtd_bdi_unmappable = {
46 .capabilities = BDI_CAP_MAP_COPY,
50 * backing device capabilities for R/O mappable devices (such as ROM)
51 * - permits private mappings, copies are taken of the data
52 * - permits non-writable shared mappings
54 static struct backing_dev_info mtd_bdi_ro_mappable = {
55 .capabilities = (BDI_CAP_MAP_COPY | BDI_CAP_MAP_DIRECT |
56 BDI_CAP_EXEC_MAP | BDI_CAP_READ_MAP),
60 * backing device capabilities for writable mappable devices (such as RAM)
61 * - permits private mappings, copies are taken of the data
62 * - permits non-writable shared mappings
64 static struct backing_dev_info mtd_bdi_rw_mappable = {
65 .capabilities = (BDI_CAP_MAP_COPY | BDI_CAP_MAP_DIRECT |
66 BDI_CAP_EXEC_MAP | BDI_CAP_READ_MAP |
70 static int mtd_cls_suspend(struct device *dev, pm_message_t state);
71 static int mtd_cls_resume(struct device *dev);
73 static struct class mtd_class = {
76 .suspend = mtd_cls_suspend,
77 .resume = mtd_cls_resume,
88 struct idr_layer id[MAX_IDR_ID];
92 #define DEFINE_IDR(name) struct idr name;
94 void idr_remove(struct idr *idp, int id)
96 if (idp->id[id].used) {
103 void *idr_find(struct idr *idp, int id)
105 if (idp->id[id].used)
106 return idp->id[id].ptr;
111 void *idr_get_next(struct idr *idp, int *next)
116 ret = idr_find(idp, id);
119 if (!idp->id[id].used)
129 int idr_alloc(struct idr *idp, void *ptr, int start, int end, gfp_t gfp_mask)
131 struct idr_layer *idl;
134 while (i < MAX_IDR_ID) {
136 if (idl->used == 0) {
148 static DEFINE_IDR(mtd_idr);
150 /* These are exported solely for the purpose of mtd_blkdevs.c. You
151 should not use them for _anything_ else */
152 DEFINE_MUTEX(mtd_table_mutex);
153 EXPORT_SYMBOL_GPL(mtd_table_mutex);
155 struct mtd_info *__mtd_next_device(int i)
157 return idr_get_next(&mtd_idr, &i);
159 EXPORT_SYMBOL_GPL(__mtd_next_device);
161 bool mtd_dev_list_updated(void)
163 if (mtd_idr.updated) {
164 mtd_idr.updated = false;
172 static LIST_HEAD(mtd_notifiers);
175 #define MTD_DEVT(index) MKDEV(MTD_CHAR_MAJOR, (index)*2)
177 /* REVISIT once MTD uses the driver model better, whoever allocates
178 * the mtd_info will probably want to use the release() hook...
180 static void mtd_release(struct device *dev)
182 struct mtd_info __maybe_unused *mtd = dev_get_drvdata(dev);
183 dev_t index = MTD_DEVT(mtd->index);
185 /* remove /dev/mtdXro node if needed */
187 device_destroy(&mtd_class, index + 1);
190 static int mtd_cls_suspend(struct device *dev, pm_message_t state)
192 struct mtd_info *mtd = dev_get_drvdata(dev);
194 return mtd ? mtd_suspend(mtd) : 0;
197 static int mtd_cls_resume(struct device *dev)
199 struct mtd_info *mtd = dev_get_drvdata(dev);
206 static ssize_t mtd_type_show(struct device *dev,
207 struct device_attribute *attr, char *buf)
209 struct mtd_info *mtd = dev_get_drvdata(dev);
234 case MTD_MLCNANDFLASH:
241 return snprintf(buf, PAGE_SIZE, "%s\n", type);
243 static DEVICE_ATTR(type, S_IRUGO, mtd_type_show, NULL);
245 static ssize_t mtd_flags_show(struct device *dev,
246 struct device_attribute *attr, char *buf)
248 struct mtd_info *mtd = dev_get_drvdata(dev);
250 return snprintf(buf, PAGE_SIZE, "0x%lx\n", (unsigned long)mtd->flags);
253 static DEVICE_ATTR(flags, S_IRUGO, mtd_flags_show, NULL);
255 static ssize_t mtd_size_show(struct device *dev,
256 struct device_attribute *attr, char *buf)
258 struct mtd_info *mtd = dev_get_drvdata(dev);
260 return snprintf(buf, PAGE_SIZE, "%llu\n",
261 (unsigned long long)mtd->size);
264 static DEVICE_ATTR(size, S_IRUGO, mtd_size_show, NULL);
266 static ssize_t mtd_erasesize_show(struct device *dev,
267 struct device_attribute *attr, char *buf)
269 struct mtd_info *mtd = dev_get_drvdata(dev);
271 return snprintf(buf, PAGE_SIZE, "%lu\n", (unsigned long)mtd->erasesize);
274 static DEVICE_ATTR(erasesize, S_IRUGO, mtd_erasesize_show, NULL);
276 static ssize_t mtd_writesize_show(struct device *dev,
277 struct device_attribute *attr, char *buf)
279 struct mtd_info *mtd = dev_get_drvdata(dev);
281 return snprintf(buf, PAGE_SIZE, "%lu\n", (unsigned long)mtd->writesize);
284 static DEVICE_ATTR(writesize, S_IRUGO, mtd_writesize_show, NULL);
286 static ssize_t mtd_subpagesize_show(struct device *dev,
287 struct device_attribute *attr, char *buf)
289 struct mtd_info *mtd = dev_get_drvdata(dev);
290 unsigned int subpagesize = mtd->writesize >> mtd->subpage_sft;
292 return snprintf(buf, PAGE_SIZE, "%u\n", subpagesize);
295 static DEVICE_ATTR(subpagesize, S_IRUGO, mtd_subpagesize_show, NULL);
297 static ssize_t mtd_oobsize_show(struct device *dev,
298 struct device_attribute *attr, char *buf)
300 struct mtd_info *mtd = dev_get_drvdata(dev);
302 return snprintf(buf, PAGE_SIZE, "%lu\n", (unsigned long)mtd->oobsize);
305 static DEVICE_ATTR(oobsize, S_IRUGO, mtd_oobsize_show, NULL);
307 static ssize_t mtd_numeraseregions_show(struct device *dev,
308 struct device_attribute *attr, char *buf)
310 struct mtd_info *mtd = dev_get_drvdata(dev);
312 return snprintf(buf, PAGE_SIZE, "%u\n", mtd->numeraseregions);
315 static DEVICE_ATTR(numeraseregions, S_IRUGO, mtd_numeraseregions_show,
318 static ssize_t mtd_name_show(struct device *dev,
319 struct device_attribute *attr, char *buf)
321 struct mtd_info *mtd = dev_get_drvdata(dev);
323 return snprintf(buf, PAGE_SIZE, "%s\n", mtd->name);
326 static DEVICE_ATTR(name, S_IRUGO, mtd_name_show, NULL);
328 static ssize_t mtd_ecc_strength_show(struct device *dev,
329 struct device_attribute *attr, char *buf)
331 struct mtd_info *mtd = dev_get_drvdata(dev);
333 return snprintf(buf, PAGE_SIZE, "%u\n", mtd->ecc_strength);
335 static DEVICE_ATTR(ecc_strength, S_IRUGO, mtd_ecc_strength_show, NULL);
337 static ssize_t mtd_bitflip_threshold_show(struct device *dev,
338 struct device_attribute *attr,
341 struct mtd_info *mtd = dev_get_drvdata(dev);
343 return snprintf(buf, PAGE_SIZE, "%u\n", mtd->bitflip_threshold);
346 static ssize_t mtd_bitflip_threshold_store(struct device *dev,
347 struct device_attribute *attr,
348 const char *buf, size_t count)
350 struct mtd_info *mtd = dev_get_drvdata(dev);
351 unsigned int bitflip_threshold;
354 retval = kstrtouint(buf, 0, &bitflip_threshold);
358 mtd->bitflip_threshold = bitflip_threshold;
361 static DEVICE_ATTR(bitflip_threshold, S_IRUGO | S_IWUSR,
362 mtd_bitflip_threshold_show,
363 mtd_bitflip_threshold_store);
365 static ssize_t mtd_ecc_step_size_show(struct device *dev,
366 struct device_attribute *attr, char *buf)
368 struct mtd_info *mtd = dev_get_drvdata(dev);
370 return snprintf(buf, PAGE_SIZE, "%u\n", mtd->ecc_step_size);
373 static DEVICE_ATTR(ecc_step_size, S_IRUGO, mtd_ecc_step_size_show, NULL);
375 static struct attribute *mtd_attrs[] = {
377 &dev_attr_flags.attr,
379 &dev_attr_erasesize.attr,
380 &dev_attr_writesize.attr,
381 &dev_attr_subpagesize.attr,
382 &dev_attr_oobsize.attr,
383 &dev_attr_numeraseregions.attr,
385 &dev_attr_ecc_strength.attr,
386 &dev_attr_ecc_step_size.attr,
387 &dev_attr_bitflip_threshold.attr,
390 ATTRIBUTE_GROUPS(mtd);
392 static struct device_type mtd_devtype = {
394 .groups = mtd_groups,
395 .release = mtd_release,
400 * add_mtd_device - register an MTD device
401 * @mtd: pointer to new MTD device info structure
403 * Add a device to the list of MTD devices present in the system, and
404 * notify each currently active MTD 'user' of its arrival. Returns
405 * zero on success or 1 on failure, which currently will only happen
406 * if there is insufficient memory or a sysfs error.
409 int add_mtd_device(struct mtd_info *mtd)
412 struct mtd_notifier *not;
417 if (!mtd->backing_dev_info) {
420 mtd->backing_dev_info = &mtd_bdi_rw_mappable;
423 mtd->backing_dev_info = &mtd_bdi_ro_mappable;
426 mtd->backing_dev_info = &mtd_bdi_unmappable;
432 BUG_ON(mtd->writesize == 0);
433 mutex_lock(&mtd_table_mutex);
435 i = idr_alloc(&mtd_idr, mtd, 0, 0, GFP_KERNEL);
442 INIT_LIST_HEAD(&mtd->partitions);
444 /* default value if not set by driver */
445 if (mtd->bitflip_threshold == 0)
446 mtd->bitflip_threshold = mtd->ecc_strength;
448 if (is_power_of_2(mtd->erasesize))
449 mtd->erasesize_shift = ffs(mtd->erasesize) - 1;
451 mtd->erasesize_shift = 0;
453 if (is_power_of_2(mtd->writesize))
454 mtd->writesize_shift = ffs(mtd->writesize) - 1;
456 mtd->writesize_shift = 0;
458 mtd->erasesize_mask = (1 << mtd->erasesize_shift) - 1;
459 mtd->writesize_mask = (1 << mtd->writesize_shift) - 1;
461 /* Some chips always power up locked. Unlock them now */
462 if ((mtd->flags & MTD_WRITEABLE) && (mtd->flags & MTD_POWERUP_LOCK)) {
463 error = mtd_unlock(mtd, 0, mtd->size);
464 if (error && error != -EOPNOTSUPP)
466 "%s: unlock failed, writes may not work\n",
471 /* Caller should have set dev.parent to match the
474 mtd->dev.type = &mtd_devtype;
475 mtd->dev.class = &mtd_class;
476 mtd->dev.devt = MTD_DEVT(i);
477 dev_set_name(&mtd->dev, "mtd%d", i);
478 dev_set_drvdata(&mtd->dev, mtd);
479 if (device_register(&mtd->dev) != 0)
483 device_create(&mtd_class, mtd->dev.parent,
487 pr_debug("mtd: Giving out device %d to %s\n", i, mtd->name);
488 /* No need to get a refcount on the module containing
489 the notifier, since we hold the mtd_table_mutex */
490 list_for_each_entry(not, &mtd_notifiers, list)
493 pr_debug("mtd: Giving out device %d to %s\n", i, mtd->name);
496 mutex_unlock(&mtd_table_mutex);
497 /* We _know_ we aren't being removed, because
498 our caller is still holding us here. So none
499 of this try_ nonsense, and no bitching about it
501 __module_get(THIS_MODULE);
506 idr_remove(&mtd_idr, i);
509 mutex_unlock(&mtd_table_mutex);
514 * del_mtd_device - unregister an MTD device
515 * @mtd: pointer to MTD device info structure
517 * Remove a device from the list of MTD devices present in the system,
518 * and notify each currently active MTD 'user' of its departure.
519 * Returns zero on success or 1 on failure, which currently will happen
520 * if the requested device does not appear to be present in the list.
523 int del_mtd_device(struct mtd_info *mtd)
527 struct mtd_notifier *not;
530 ret = del_mtd_partitions(mtd);
532 debug("Failed to delete MTD partitions attached to %s (err %d)\n",
537 mutex_lock(&mtd_table_mutex);
539 if (idr_find(&mtd_idr, mtd->index) != mtd) {
545 /* No need to get a refcount on the module containing
546 the notifier, since we hold the mtd_table_mutex */
547 list_for_each_entry(not, &mtd_notifiers, list)
552 printk(KERN_NOTICE "Removing MTD device #%d (%s) with use count %d\n",
553 mtd->index, mtd->name, mtd->usecount);
557 device_unregister(&mtd->dev);
560 idr_remove(&mtd_idr, mtd->index);
562 module_put(THIS_MODULE);
567 mutex_unlock(&mtd_table_mutex);
573 * mtd_device_parse_register - parse partitions and register an MTD device.
575 * @mtd: the MTD device to register
576 * @types: the list of MTD partition probes to try, see
577 * 'parse_mtd_partitions()' for more information
578 * @parser_data: MTD partition parser-specific data
579 * @parts: fallback partition information to register, if parsing fails;
580 * only valid if %nr_parts > %0
581 * @nr_parts: the number of partitions in parts, if zero then the full
582 * MTD device is registered if no partition info is found
584 * This function aggregates MTD partitions parsing (done by
585 * 'parse_mtd_partitions()') and MTD device and partitions registering. It
586 * basically follows the most common pattern found in many MTD drivers:
588 * * It first tries to probe partitions on MTD device @mtd using parsers
589 * specified in @types (if @types is %NULL, then the default list of parsers
590 * is used, see 'parse_mtd_partitions()' for more information). If none are
591 * found this functions tries to fallback to information specified in
593 * * If any partitioning info was found, this function registers the found
595 * * If no partitions were found this function just registers the MTD device
598 * Returns zero in case of success and a negative error code in case of failure.
600 int mtd_device_parse_register(struct mtd_info *mtd, const char * const *types,
601 struct mtd_part_parser_data *parser_data,
602 const struct mtd_partition *parts,
606 struct mtd_partition *real_parts;
608 err = parse_mtd_partitions(mtd, types, &real_parts, parser_data);
609 if (err <= 0 && nr_parts && parts) {
610 real_parts = kmemdup(parts, sizeof(*parts) * nr_parts,
619 err = add_mtd_partitions(mtd, real_parts, err);
621 } else if (err == 0) {
622 err = add_mtd_device(mtd);
629 EXPORT_SYMBOL_GPL(mtd_device_parse_register);
632 * mtd_device_unregister - unregister an existing MTD device.
634 * @master: the MTD device to unregister. This will unregister both the master
635 * and any partitions if registered.
637 int mtd_device_unregister(struct mtd_info *master)
641 err = del_mtd_partitions(master);
645 if (!device_is_registered(&master->dev))
648 return del_mtd_device(master);
650 EXPORT_SYMBOL_GPL(mtd_device_unregister);
653 * register_mtd_user - register a 'user' of MTD devices.
654 * @new: pointer to notifier info structure
656 * Registers a pair of callbacks function to be called upon addition
657 * or removal of MTD devices. Causes the 'add' callback to be immediately
658 * invoked for each MTD device currently present in the system.
660 void register_mtd_user (struct mtd_notifier *new)
662 struct mtd_info *mtd;
664 mutex_lock(&mtd_table_mutex);
666 list_add(&new->list, &mtd_notifiers);
668 __module_get(THIS_MODULE);
670 mtd_for_each_device(mtd)
673 mutex_unlock(&mtd_table_mutex);
675 EXPORT_SYMBOL_GPL(register_mtd_user);
678 * unregister_mtd_user - unregister a 'user' of MTD devices.
679 * @old: pointer to notifier info structure
681 * Removes a callback function pair from the list of 'users' to be
682 * notified upon addition or removal of MTD devices. Causes the
683 * 'remove' callback to be immediately invoked for each MTD device
684 * currently present in the system.
686 int unregister_mtd_user (struct mtd_notifier *old)
688 struct mtd_info *mtd;
690 mutex_lock(&mtd_table_mutex);
692 module_put(THIS_MODULE);
694 mtd_for_each_device(mtd)
697 list_del(&old->list);
698 mutex_unlock(&mtd_table_mutex);
701 EXPORT_SYMBOL_GPL(unregister_mtd_user);
705 * get_mtd_device - obtain a validated handle for an MTD device
706 * @mtd: last known address of the required MTD device
707 * @num: internal device number of the required MTD device
709 * Given a number and NULL address, return the num'th entry in the device
710 * table, if any. Given an address and num == -1, search the device table
711 * for a device with that address and return if it's still present. Given
712 * both, return the num'th driver only if its address matches. Return
715 struct mtd_info *get_mtd_device(struct mtd_info *mtd, int num)
717 struct mtd_info *ret = NULL, *other;
720 mutex_lock(&mtd_table_mutex);
723 mtd_for_each_device(other) {
729 } else if (num >= 0) {
730 ret = idr_find(&mtd_idr, num);
731 if (mtd && mtd != ret)
740 err = __get_mtd_device(ret);
744 mutex_unlock(&mtd_table_mutex);
747 EXPORT_SYMBOL_GPL(get_mtd_device);
750 int __get_mtd_device(struct mtd_info *mtd)
754 if (!try_module_get(mtd->owner))
757 if (mtd->_get_device) {
758 err = mtd->_get_device(mtd);
761 module_put(mtd->owner);
768 EXPORT_SYMBOL_GPL(__get_mtd_device);
771 * get_mtd_device_nm - obtain a validated handle for an MTD device by
773 * @name: MTD device name to open
775 * This function returns MTD device description structure in case of
776 * success and an error code in case of failure.
778 struct mtd_info *get_mtd_device_nm(const char *name)
781 struct mtd_info *mtd = NULL, *other;
783 mutex_lock(&mtd_table_mutex);
785 mtd_for_each_device(other) {
786 if (!strcmp(name, other->name)) {
795 err = __get_mtd_device(mtd);
799 mutex_unlock(&mtd_table_mutex);
803 mutex_unlock(&mtd_table_mutex);
806 EXPORT_SYMBOL_GPL(get_mtd_device_nm);
808 #if defined(CONFIG_CMD_MTDPARTS_SPREAD)
810 * mtd_get_len_incl_bad
812 * Check if length including bad blocks fits into device.
814 * @param mtd an MTD device
815 * @param offset offset in flash
816 * @param length image length
817 * @return image length including bad blocks in *len_incl_bad and whether or not
818 * the length returned was truncated in *truncated
820 void mtd_get_len_incl_bad(struct mtd_info *mtd, uint64_t offset,
821 const uint64_t length, uint64_t *len_incl_bad,
827 if (!mtd->_block_isbad) {
828 *len_incl_bad = length;
832 uint64_t len_excl_bad = 0;
835 while (len_excl_bad < length) {
836 if (offset >= mtd->size) {
841 block_len = mtd->erasesize - (offset & (mtd->erasesize - 1));
843 if (!mtd->_block_isbad(mtd, offset & ~(mtd->erasesize - 1)))
844 len_excl_bad += block_len;
846 *len_incl_bad += block_len;
850 #endif /* defined(CONFIG_CMD_MTDPARTS_SPREAD) */
852 void put_mtd_device(struct mtd_info *mtd)
854 mutex_lock(&mtd_table_mutex);
855 __put_mtd_device(mtd);
856 mutex_unlock(&mtd_table_mutex);
859 EXPORT_SYMBOL_GPL(put_mtd_device);
861 void __put_mtd_device(struct mtd_info *mtd)
864 BUG_ON(mtd->usecount < 0);
866 if (mtd->_put_device)
867 mtd->_put_device(mtd);
869 module_put(mtd->owner);
871 EXPORT_SYMBOL_GPL(__put_mtd_device);
874 * Erase is an asynchronous operation. Device drivers are supposed
875 * to call instr->callback() whenever the operation completes, even
876 * if it completes with a failure.
877 * Callers are supposed to pass a callback function and wait for it
878 * to be called before writing to the block.
880 int mtd_erase(struct mtd_info *mtd, struct erase_info *instr)
882 if (instr->addr > mtd->size || instr->len > mtd->size - instr->addr)
884 if (!(mtd->flags & MTD_WRITEABLE))
886 instr->fail_addr = MTD_FAIL_ADDR_UNKNOWN;
888 instr->state = MTD_ERASE_DONE;
889 mtd_erase_callback(instr);
892 return mtd->_erase(mtd, instr);
894 EXPORT_SYMBOL_GPL(mtd_erase);
898 * This stuff for eXecute-In-Place. phys is optional and may be set to NULL.
900 int mtd_point(struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen,
901 void **virt, resource_size_t *phys)
909 if (from < 0 || from > mtd->size || len > mtd->size - from)
913 return mtd->_point(mtd, from, len, retlen, virt, phys);
915 EXPORT_SYMBOL_GPL(mtd_point);
917 /* We probably shouldn't allow XIP if the unpoint isn't a NULL */
918 int mtd_unpoint(struct mtd_info *mtd, loff_t from, size_t len)
922 if (from < 0 || from > mtd->size || len > mtd->size - from)
926 return mtd->_unpoint(mtd, from, len);
928 EXPORT_SYMBOL_GPL(mtd_unpoint);
932 * Allow NOMMU mmap() to directly map the device (if not NULL)
933 * - return the address to which the offset maps
934 * - return -ENOSYS to indicate refusal to do the mapping
936 unsigned long mtd_get_unmapped_area(struct mtd_info *mtd, unsigned long len,
937 unsigned long offset, unsigned long flags)
939 if (!mtd->_get_unmapped_area)
941 if (offset > mtd->size || len > mtd->size - offset)
943 return mtd->_get_unmapped_area(mtd, len, offset, flags);
945 EXPORT_SYMBOL_GPL(mtd_get_unmapped_area);
947 int mtd_read(struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen,
952 if (from < 0 || from > mtd->size || len > mtd->size - from)
958 * In the absence of an error, drivers return a non-negative integer
959 * representing the maximum number of bitflips that were corrected on
960 * any one ecc region (if applicable; zero otherwise).
963 ret_code = mtd->_read(mtd, from, len, retlen, buf);
964 } else if (mtd->_read_oob) {
965 struct mtd_oob_ops ops = {
970 ret_code = mtd->_read_oob(mtd, from, &ops);
971 *retlen = ops.retlen;
976 if (unlikely(ret_code < 0))
978 if (mtd->ecc_strength == 0)
979 return 0; /* device lacks ecc */
980 return ret_code >= mtd->bitflip_threshold ? -EUCLEAN : 0;
982 EXPORT_SYMBOL_GPL(mtd_read);
984 int mtd_write(struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen,
988 if (to < 0 || to > mtd->size || len > mtd->size - to)
990 if ((!mtd->_write && !mtd->_write_oob) ||
991 !(mtd->flags & MTD_WRITEABLE))
997 struct mtd_oob_ops ops = {
1003 ret = mtd->_write_oob(mtd, to, &ops);
1004 *retlen = ops.retlen;
1008 return mtd->_write(mtd, to, len, retlen, buf);
1010 EXPORT_SYMBOL_GPL(mtd_write);
1013 * In blackbox flight recorder like scenarios we want to make successful writes
1014 * in interrupt context. panic_write() is only intended to be called when its
1015 * known the kernel is about to panic and we need the write to succeed. Since
1016 * the kernel is not going to be running for much longer, this function can
1017 * break locks and delay to ensure the write succeeds (but not sleep).
1019 int mtd_panic_write(struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen,
1023 if (!mtd->_panic_write)
1025 if (to < 0 || to > mtd->size || len > mtd->size - to)
1027 if (!(mtd->flags & MTD_WRITEABLE))
1031 return mtd->_panic_write(mtd, to, len, retlen, buf);
1033 EXPORT_SYMBOL_GPL(mtd_panic_write);
1035 static int mtd_check_oob_ops(struct mtd_info *mtd, loff_t offs,
1036 struct mtd_oob_ops *ops)
1039 * Some users are setting ->datbuf or ->oobbuf to NULL, but are leaving
1040 * ->len or ->ooblen uninitialized. Force ->len and ->ooblen to 0 in
1049 if (offs < 0 || offs + ops->len > mtd->size)
1055 if (ops->ooboffs >= mtd_oobavail(mtd, ops))
1058 maxooblen = ((size_t)(mtd_div_by_ws(mtd->size, mtd) -
1059 mtd_div_by_ws(offs, mtd)) *
1060 mtd_oobavail(mtd, ops)) - ops->ooboffs;
1061 if (ops->ooblen > maxooblen)
1068 int mtd_read_oob(struct mtd_info *mtd, loff_t from, struct mtd_oob_ops *ops)
1071 ops->retlen = ops->oobretlen = 0;
1073 ret_code = mtd_check_oob_ops(mtd, from, ops);
1077 /* Check the validity of a potential fallback on mtd->_read */
1078 if (!mtd->_read_oob && (!mtd->_read || ops->oobbuf))
1082 ret_code = mtd->_read_oob(mtd, from, ops);
1084 ret_code = mtd->_read(mtd, from, ops->len, &ops->retlen,
1088 * In cases where ops->datbuf != NULL, mtd->_read_oob() has semantics
1089 * similar to mtd->_read(), returning a non-negative integer
1090 * representing max bitflips. In other cases, mtd->_read_oob() may
1091 * return -EUCLEAN. In all cases, perform similar logic to mtd_read().
1093 if (unlikely(ret_code < 0))
1095 if (mtd->ecc_strength == 0)
1096 return 0; /* device lacks ecc */
1097 return ret_code >= mtd->bitflip_threshold ? -EUCLEAN : 0;
1099 EXPORT_SYMBOL_GPL(mtd_read_oob);
1101 int mtd_write_oob(struct mtd_info *mtd, loff_t to,
1102 struct mtd_oob_ops *ops)
1106 ops->retlen = ops->oobretlen = 0;
1108 if (!(mtd->flags & MTD_WRITEABLE))
1111 ret = mtd_check_oob_ops(mtd, to, ops);
1115 /* Check the validity of a potential fallback on mtd->_write */
1116 if (!mtd->_write_oob && (!mtd->_write || ops->oobbuf))
1119 if (mtd->_write_oob)
1120 return mtd->_write_oob(mtd, to, ops);
1122 return mtd->_write(mtd, to, ops->len, &ops->retlen,
1125 EXPORT_SYMBOL_GPL(mtd_write_oob);
1128 * mtd_ooblayout_ecc - Get the OOB region definition of a specific ECC section
1129 * @mtd: MTD device structure
1130 * @section: ECC section. Depending on the layout you may have all the ECC
1131 * bytes stored in a single contiguous section, or one section
1132 * per ECC chunk (and sometime several sections for a single ECC
1134 * @oobecc: OOB region struct filled with the appropriate ECC position
1137 * This function returns ECC section information in the OOB area. If you want
1138 * to get all the ECC bytes information, then you should call
1139 * mtd_ooblayout_ecc(mtd, section++, oobecc) until it returns -ERANGE.
1141 * Returns zero on success, a negative error code otherwise.
1143 int mtd_ooblayout_ecc(struct mtd_info *mtd, int section,
1144 struct mtd_oob_region *oobecc)
1146 memset(oobecc, 0, sizeof(*oobecc));
1148 if (!mtd || section < 0)
1151 if (!mtd->ooblayout || !mtd->ooblayout->ecc)
1154 return mtd->ooblayout->ecc(mtd, section, oobecc);
1156 EXPORT_SYMBOL_GPL(mtd_ooblayout_ecc);
1159 * mtd_ooblayout_free - Get the OOB region definition of a specific free
1161 * @mtd: MTD device structure
1162 * @section: Free section you are interested in. Depending on the layout
1163 * you may have all the free bytes stored in a single contiguous
1164 * section, or one section per ECC chunk plus an extra section
1165 * for the remaining bytes (or other funky layout).
1166 * @oobfree: OOB region struct filled with the appropriate free position
1169 * This function returns free bytes position in the OOB area. If you want
1170 * to get all the free bytes information, then you should call
1171 * mtd_ooblayout_free(mtd, section++, oobfree) until it returns -ERANGE.
1173 * Returns zero on success, a negative error code otherwise.
1175 int mtd_ooblayout_free(struct mtd_info *mtd, int section,
1176 struct mtd_oob_region *oobfree)
1178 memset(oobfree, 0, sizeof(*oobfree));
1180 if (!mtd || section < 0)
1183 if (!mtd->ooblayout || !mtd->ooblayout->rfree)
1186 return mtd->ooblayout->rfree(mtd, section, oobfree);
1188 EXPORT_SYMBOL_GPL(mtd_ooblayout_free);
1191 * mtd_ooblayout_find_region - Find the region attached to a specific byte
1192 * @mtd: mtd info structure
1193 * @byte: the byte we are searching for
1194 * @sectionp: pointer where the section id will be stored
1195 * @oobregion: used to retrieve the ECC position
1196 * @iter: iterator function. Should be either mtd_ooblayout_free or
1197 * mtd_ooblayout_ecc depending on the region type you're searching for
1199 * This function returns the section id and oobregion information of a
1200 * specific byte. For example, say you want to know where the 4th ECC byte is
1201 * stored, you'll use:
1203 * mtd_ooblayout_find_region(mtd, 3, §ion, &oobregion, mtd_ooblayout_ecc);
1205 * Returns zero on success, a negative error code otherwise.
1207 static int mtd_ooblayout_find_region(struct mtd_info *mtd, int byte,
1208 int *sectionp, struct mtd_oob_region *oobregion,
1209 int (*iter)(struct mtd_info *,
1211 struct mtd_oob_region *oobregion))
1213 int pos = 0, ret, section = 0;
1215 memset(oobregion, 0, sizeof(*oobregion));
1218 ret = iter(mtd, section, oobregion);
1222 if (pos + oobregion->length > byte)
1225 pos += oobregion->length;
1230 * Adjust region info to make it start at the beginning at the
1233 oobregion->offset += byte - pos;
1234 oobregion->length -= byte - pos;
1235 *sectionp = section;
1241 * mtd_ooblayout_find_eccregion - Find the ECC region attached to a specific
1243 * @mtd: mtd info structure
1244 * @eccbyte: the byte we are searching for
1245 * @sectionp: pointer where the section id will be stored
1246 * @oobregion: OOB region information
1248 * Works like mtd_ooblayout_find_region() except it searches for a specific ECC
1251 * Returns zero on success, a negative error code otherwise.
1253 int mtd_ooblayout_find_eccregion(struct mtd_info *mtd, int eccbyte,
1255 struct mtd_oob_region *oobregion)
1257 return mtd_ooblayout_find_region(mtd, eccbyte, section, oobregion,
1260 EXPORT_SYMBOL_GPL(mtd_ooblayout_find_eccregion);
1263 * mtd_ooblayout_get_bytes - Extract OOB bytes from the oob buffer
1264 * @mtd: mtd info structure
1265 * @buf: destination buffer to store OOB bytes
1266 * @oobbuf: OOB buffer
1267 * @start: first byte to retrieve
1268 * @nbytes: number of bytes to retrieve
1269 * @iter: section iterator
1271 * Extract bytes attached to a specific category (ECC or free)
1272 * from the OOB buffer and copy them into buf.
1274 * Returns zero on success, a negative error code otherwise.
1276 static int mtd_ooblayout_get_bytes(struct mtd_info *mtd, u8 *buf,
1277 const u8 *oobbuf, int start, int nbytes,
1278 int (*iter)(struct mtd_info *,
1280 struct mtd_oob_region *oobregion))
1282 struct mtd_oob_region oobregion;
1285 ret = mtd_ooblayout_find_region(mtd, start, §ion,
1291 cnt = min_t(int, nbytes, oobregion.length);
1292 memcpy(buf, oobbuf + oobregion.offset, cnt);
1299 ret = iter(mtd, ++section, &oobregion);
1306 * mtd_ooblayout_set_bytes - put OOB bytes into the oob buffer
1307 * @mtd: mtd info structure
1308 * @buf: source buffer to get OOB bytes from
1309 * @oobbuf: OOB buffer
1310 * @start: first OOB byte to set
1311 * @nbytes: number of OOB bytes to set
1312 * @iter: section iterator
1314 * Fill the OOB buffer with data provided in buf. The category (ECC or free)
1315 * is selected by passing the appropriate iterator.
1317 * Returns zero on success, a negative error code otherwise.
1319 static int mtd_ooblayout_set_bytes(struct mtd_info *mtd, const u8 *buf,
1320 u8 *oobbuf, int start, int nbytes,
1321 int (*iter)(struct mtd_info *,
1323 struct mtd_oob_region *oobregion))
1325 struct mtd_oob_region oobregion;
1328 ret = mtd_ooblayout_find_region(mtd, start, §ion,
1334 cnt = min_t(int, nbytes, oobregion.length);
1335 memcpy(oobbuf + oobregion.offset, buf, cnt);
1342 ret = iter(mtd, ++section, &oobregion);
1349 * mtd_ooblayout_count_bytes - count the number of bytes in a OOB category
1350 * @mtd: mtd info structure
1351 * @iter: category iterator
1353 * Count the number of bytes in a given category.
1355 * Returns a positive value on success, a negative error code otherwise.
1357 static int mtd_ooblayout_count_bytes(struct mtd_info *mtd,
1358 int (*iter)(struct mtd_info *,
1360 struct mtd_oob_region *oobregion))
1362 struct mtd_oob_region oobregion;
1363 int section = 0, ret, nbytes = 0;
1366 ret = iter(mtd, section++, &oobregion);
1373 nbytes += oobregion.length;
1380 * mtd_ooblayout_get_eccbytes - extract ECC bytes from the oob buffer
1381 * @mtd: mtd info structure
1382 * @eccbuf: destination buffer to store ECC bytes
1383 * @oobbuf: OOB buffer
1384 * @start: first ECC byte to retrieve
1385 * @nbytes: number of ECC bytes to retrieve
1387 * Works like mtd_ooblayout_get_bytes(), except it acts on ECC bytes.
1389 * Returns zero on success, a negative error code otherwise.
1391 int mtd_ooblayout_get_eccbytes(struct mtd_info *mtd, u8 *eccbuf,
1392 const u8 *oobbuf, int start, int nbytes)
1394 return mtd_ooblayout_get_bytes(mtd, eccbuf, oobbuf, start, nbytes,
1397 EXPORT_SYMBOL_GPL(mtd_ooblayout_get_eccbytes);
1400 * mtd_ooblayout_set_eccbytes - set ECC bytes into the oob buffer
1401 * @mtd: mtd info structure
1402 * @eccbuf: source buffer to get ECC bytes from
1403 * @oobbuf: OOB buffer
1404 * @start: first ECC byte to set
1405 * @nbytes: number of ECC bytes to set
1407 * Works like mtd_ooblayout_set_bytes(), except it acts on ECC bytes.
1409 * Returns zero on success, a negative error code otherwise.
1411 int mtd_ooblayout_set_eccbytes(struct mtd_info *mtd, const u8 *eccbuf,
1412 u8 *oobbuf, int start, int nbytes)
1414 return mtd_ooblayout_set_bytes(mtd, eccbuf, oobbuf, start, nbytes,
1417 EXPORT_SYMBOL_GPL(mtd_ooblayout_set_eccbytes);
1420 * mtd_ooblayout_get_databytes - extract data bytes from the oob buffer
1421 * @mtd: mtd info structure
1422 * @databuf: destination buffer to store ECC bytes
1423 * @oobbuf: OOB buffer
1424 * @start: first ECC byte to retrieve
1425 * @nbytes: number of ECC bytes to retrieve
1427 * Works like mtd_ooblayout_get_bytes(), except it acts on free bytes.
1429 * Returns zero on success, a negative error code otherwise.
1431 int mtd_ooblayout_get_databytes(struct mtd_info *mtd, u8 *databuf,
1432 const u8 *oobbuf, int start, int nbytes)
1434 return mtd_ooblayout_get_bytes(mtd, databuf, oobbuf, start, nbytes,
1435 mtd_ooblayout_free);
1437 EXPORT_SYMBOL_GPL(mtd_ooblayout_get_databytes);
1440 * mtd_ooblayout_get_eccbytes - set data bytes into the oob buffer
1441 * @mtd: mtd info structure
1442 * @eccbuf: source buffer to get data bytes from
1443 * @oobbuf: OOB buffer
1444 * @start: first ECC byte to set
1445 * @nbytes: number of ECC bytes to set
1447 * Works like mtd_ooblayout_get_bytes(), except it acts on free bytes.
1449 * Returns zero on success, a negative error code otherwise.
1451 int mtd_ooblayout_set_databytes(struct mtd_info *mtd, const u8 *databuf,
1452 u8 *oobbuf, int start, int nbytes)
1454 return mtd_ooblayout_set_bytes(mtd, databuf, oobbuf, start, nbytes,
1455 mtd_ooblayout_free);
1457 EXPORT_SYMBOL_GPL(mtd_ooblayout_set_databytes);
1460 * mtd_ooblayout_count_freebytes - count the number of free bytes in OOB
1461 * @mtd: mtd info structure
1463 * Works like mtd_ooblayout_count_bytes(), except it count free bytes.
1465 * Returns zero on success, a negative error code otherwise.
1467 int mtd_ooblayout_count_freebytes(struct mtd_info *mtd)
1469 return mtd_ooblayout_count_bytes(mtd, mtd_ooblayout_free);
1471 EXPORT_SYMBOL_GPL(mtd_ooblayout_count_freebytes);
1474 * mtd_ooblayout_count_freebytes - count the number of ECC bytes in OOB
1475 * @mtd: mtd info structure
1477 * Works like mtd_ooblayout_count_bytes(), except it count ECC bytes.
1479 * Returns zero on success, a negative error code otherwise.
1481 int mtd_ooblayout_count_eccbytes(struct mtd_info *mtd)
1483 return mtd_ooblayout_count_bytes(mtd, mtd_ooblayout_ecc);
1485 EXPORT_SYMBOL_GPL(mtd_ooblayout_count_eccbytes);
1488 * Method to access the protection register area, present in some flash
1489 * devices. The user data is one time programmable but the factory data is read
1492 int mtd_get_fact_prot_info(struct mtd_info *mtd, size_t len, size_t *retlen,
1493 struct otp_info *buf)
1495 if (!mtd->_get_fact_prot_info)
1499 return mtd->_get_fact_prot_info(mtd, len, retlen, buf);
1501 EXPORT_SYMBOL_GPL(mtd_get_fact_prot_info);
1503 int mtd_read_fact_prot_reg(struct mtd_info *mtd, loff_t from, size_t len,
1504 size_t *retlen, u_char *buf)
1507 if (!mtd->_read_fact_prot_reg)
1511 return mtd->_read_fact_prot_reg(mtd, from, len, retlen, buf);
1513 EXPORT_SYMBOL_GPL(mtd_read_fact_prot_reg);
1515 int mtd_get_user_prot_info(struct mtd_info *mtd, size_t len, size_t *retlen,
1516 struct otp_info *buf)
1518 if (!mtd->_get_user_prot_info)
1522 return mtd->_get_user_prot_info(mtd, len, retlen, buf);
1524 EXPORT_SYMBOL_GPL(mtd_get_user_prot_info);
1526 int mtd_read_user_prot_reg(struct mtd_info *mtd, loff_t from, size_t len,
1527 size_t *retlen, u_char *buf)
1530 if (!mtd->_read_user_prot_reg)
1534 return mtd->_read_user_prot_reg(mtd, from, len, retlen, buf);
1536 EXPORT_SYMBOL_GPL(mtd_read_user_prot_reg);
1538 int mtd_write_user_prot_reg(struct mtd_info *mtd, loff_t to, size_t len,
1539 size_t *retlen, u_char *buf)
1544 if (!mtd->_write_user_prot_reg)
1548 ret = mtd->_write_user_prot_reg(mtd, to, len, retlen, buf);
1553 * If no data could be written at all, we are out of memory and
1554 * must return -ENOSPC.
1556 return (*retlen) ? 0 : -ENOSPC;
1558 EXPORT_SYMBOL_GPL(mtd_write_user_prot_reg);
1560 int mtd_lock_user_prot_reg(struct mtd_info *mtd, loff_t from, size_t len)
1562 if (!mtd->_lock_user_prot_reg)
1566 return mtd->_lock_user_prot_reg(mtd, from, len);
1568 EXPORT_SYMBOL_GPL(mtd_lock_user_prot_reg);
1570 /* Chip-supported device locking */
1571 int mtd_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
1575 if (ofs < 0 || ofs > mtd->size || len > mtd->size - ofs)
1579 return mtd->_lock(mtd, ofs, len);
1581 EXPORT_SYMBOL_GPL(mtd_lock);
1583 int mtd_unlock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
1587 if (ofs < 0 || ofs > mtd->size || len > mtd->size - ofs)
1591 return mtd->_unlock(mtd, ofs, len);
1593 EXPORT_SYMBOL_GPL(mtd_unlock);
1595 int mtd_is_locked(struct mtd_info *mtd, loff_t ofs, uint64_t len)
1597 if (!mtd->_is_locked)
1599 if (ofs < 0 || ofs > mtd->size || len > mtd->size - ofs)
1603 return mtd->_is_locked(mtd, ofs, len);
1605 EXPORT_SYMBOL_GPL(mtd_is_locked);
1607 int mtd_block_isreserved(struct mtd_info *mtd, loff_t ofs)
1609 if (ofs < 0 || ofs > mtd->size)
1611 if (!mtd->_block_isreserved)
1613 return mtd->_block_isreserved(mtd, ofs);
1615 EXPORT_SYMBOL_GPL(mtd_block_isreserved);
1617 int mtd_block_isbad(struct mtd_info *mtd, loff_t ofs)
1619 if (ofs < 0 || ofs > mtd->size)
1621 if (!mtd->_block_isbad)
1623 return mtd->_block_isbad(mtd, ofs);
1625 EXPORT_SYMBOL_GPL(mtd_block_isbad);
1627 int mtd_block_markbad(struct mtd_info *mtd, loff_t ofs)
1629 if (!mtd->_block_markbad)
1631 if (ofs < 0 || ofs > mtd->size)
1633 if (!(mtd->flags & MTD_WRITEABLE))
1635 return mtd->_block_markbad(mtd, ofs);
1637 EXPORT_SYMBOL_GPL(mtd_block_markbad);
1641 * default_mtd_writev - the default writev method
1642 * @mtd: mtd device description object pointer
1643 * @vecs: the vectors to write
1644 * @count: count of vectors in @vecs
1645 * @to: the MTD device offset to write to
1646 * @retlen: on exit contains the count of bytes written to the MTD device.
1648 * This function returns zero in case of success and a negative error code in
1651 static int default_mtd_writev(struct mtd_info *mtd, const struct kvec *vecs,
1652 unsigned long count, loff_t to, size_t *retlen)
1655 size_t totlen = 0, thislen;
1658 for (i = 0; i < count; i++) {
1659 if (!vecs[i].iov_len)
1661 ret = mtd_write(mtd, to, vecs[i].iov_len, &thislen,
1664 if (ret || thislen != vecs[i].iov_len)
1666 to += vecs[i].iov_len;
1673 * mtd_writev - the vector-based MTD write method
1674 * @mtd: mtd device description object pointer
1675 * @vecs: the vectors to write
1676 * @count: count of vectors in @vecs
1677 * @to: the MTD device offset to write to
1678 * @retlen: on exit contains the count of bytes written to the MTD device.
1680 * This function returns zero in case of success and a negative error code in
1683 int mtd_writev(struct mtd_info *mtd, const struct kvec *vecs,
1684 unsigned long count, loff_t to, size_t *retlen)
1687 if (!(mtd->flags & MTD_WRITEABLE))
1690 return default_mtd_writev(mtd, vecs, count, to, retlen);
1691 return mtd->_writev(mtd, vecs, count, to, retlen);
1693 EXPORT_SYMBOL_GPL(mtd_writev);
1696 * mtd_kmalloc_up_to - allocate a contiguous buffer up to the specified size
1697 * @mtd: mtd device description object pointer
1698 * @size: a pointer to the ideal or maximum size of the allocation, points
1699 * to the actual allocation size on success.
1701 * This routine attempts to allocate a contiguous kernel buffer up to
1702 * the specified size, backing off the size of the request exponentially
1703 * until the request succeeds or until the allocation size falls below
1704 * the system page size. This attempts to make sure it does not adversely
1705 * impact system performance, so when allocating more than one page, we
1706 * ask the memory allocator to avoid re-trying, swapping, writing back
1707 * or performing I/O.
1709 * Note, this function also makes sure that the allocated buffer is aligned to
1710 * the MTD device's min. I/O unit, i.e. the "mtd->writesize" value.
1712 * This is called, for example by mtd_{read,write} and jffs2_scan_medium,
1713 * to handle smaller (i.e. degraded) buffer allocations under low- or
1714 * fragmented-memory situations where such reduced allocations, from a
1715 * requested ideal, are allowed.
1717 * Returns a pointer to the allocated buffer on success; otherwise, NULL.
1719 void *mtd_kmalloc_up_to(const struct mtd_info *mtd, size_t *size)
1721 gfp_t flags = __GFP_NOWARN | __GFP_WAIT |
1722 __GFP_NORETRY | __GFP_NO_KSWAPD;
1723 size_t min_alloc = max_t(size_t, mtd->writesize, PAGE_SIZE);
1726 *size = min_t(size_t, *size, KMALLOC_MAX_SIZE);
1728 while (*size > min_alloc) {
1729 kbuf = kmalloc(*size, flags);
1734 *size = ALIGN(*size, mtd->writesize);
1738 * For the last resort allocation allow 'kmalloc()' to do all sorts of
1739 * things (write-back, dropping caches, etc) by using GFP_KERNEL.
1741 return kmalloc(*size, GFP_KERNEL);
1743 EXPORT_SYMBOL_GPL(mtd_kmalloc_up_to);
1746 #ifdef CONFIG_PROC_FS
1748 /*====================================================================*/
1749 /* Support for /proc/mtd */
1751 static int mtd_proc_show(struct seq_file *m, void *v)
1753 struct mtd_info *mtd;
1755 seq_puts(m, "dev: size erasesize name\n");
1756 mutex_lock(&mtd_table_mutex);
1757 mtd_for_each_device(mtd) {
1758 seq_printf(m, "mtd%d: %8.8llx %8.8x \"%s\"\n",
1759 mtd->index, (unsigned long long)mtd->size,
1760 mtd->erasesize, mtd->name);
1762 mutex_unlock(&mtd_table_mutex);
1766 static int mtd_proc_open(struct inode *inode, struct file *file)
1768 return single_open(file, mtd_proc_show, NULL);
1771 static const struct file_operations mtd_proc_ops = {
1772 .open = mtd_proc_open,
1774 .llseek = seq_lseek,
1775 .release = single_release,
1777 #endif /* CONFIG_PROC_FS */
1779 /*====================================================================*/
1783 static int __init mtd_bdi_init(struct backing_dev_info *bdi, const char *name)
1787 ret = bdi_init(bdi);
1789 ret = bdi_register(bdi, NULL, "%s", name);
1797 static struct proc_dir_entry *proc_mtd;
1799 static int __init init_mtd(void)
1803 ret = class_register(&mtd_class);
1807 ret = mtd_bdi_init(&mtd_bdi_unmappable, "mtd-unmap");
1811 ret = mtd_bdi_init(&mtd_bdi_ro_mappable, "mtd-romap");
1815 ret = mtd_bdi_init(&mtd_bdi_rw_mappable, "mtd-rwmap");
1819 proc_mtd = proc_create("mtd", 0, NULL, &mtd_proc_ops);
1821 ret = init_mtdchar();
1829 remove_proc_entry("mtd", NULL);
1831 bdi_destroy(&mtd_bdi_ro_mappable);
1833 bdi_destroy(&mtd_bdi_unmappable);
1835 class_unregister(&mtd_class);
1837 pr_err("Error registering mtd class or bdi: %d\n", ret);
1841 static void __exit cleanup_mtd(void)
1845 remove_proc_entry("mtd", NULL);
1846 class_unregister(&mtd_class);
1847 bdi_destroy(&mtd_bdi_unmappable);
1848 bdi_destroy(&mtd_bdi_ro_mappable);
1849 bdi_destroy(&mtd_bdi_rw_mappable);
1852 module_init(init_mtd);
1853 module_exit(cleanup_mtd);
1856 MODULE_LICENSE("GPL");
1857 MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
1858 MODULE_DESCRIPTION("Core MTD registration and access routines");